This invention relates to a process and apparatus for adsorbing one or more specific components from a mixture containing at least one other component and thereby separating the specific components from the mixture. More particularly, the invention is directed to improved adsorption by the use of graded channel sizes and graded adsorbent concentration diminishing along the flow direction of the mixture stream passed through the adsorber.
Adsorption technology is well developed and employed widely in industry. Two basic types of apparatus are in use: fixed beds of adsorbent particles and rotary wheels containing an adsorbent. Fixed beds are usually used in pairs so that while one bed is in operation for the adsorption of at least one component from a mixture containing that component, the other bed is being regenerated by desorption of the captured component. Periodically, the roles of the two beds are switched; the regenerated bed becomes the adsorber bed and the other bed undergoes regeneration. Hence, such paired adsorber beds are commonly called swing adsorbers.
Rotary wheel adsorbers are designed to permit the flow of a gaseous stream containing a component that is to be removed therefrom through one sector of the cylindrical adsorber, while a purging gaseous stream flows through another sector of the rotary wheel to effect regeneration of the adsorbent by dislodging the adsorbate. U.S. Pat. Nos. 3,780,498; 4,398,927 and 5,512,083 are illustrative of the highly developed rotary adsorber art. The numerous citations in these patents attest to the extensive adsorption technology.
In spite of the numerous proposals for improvements in adsorption technology, there remains an industrial demand for adsorbers of lower cost, less weight and floor space, and greater reliability. The invention is responsive to these needs.
Accordingly, a principal object of the invention is to arrange the adsorbent in a configuration that minimizes pressure drop of a gaseous mixture passed therethrough while the efficacy of the adsorbent is enhanced.
Another important object is to provide an adsorption process and apparatus of improved economic attractiveness.
A further object is to provide more compact and lighter adsorbers.
These and other features and advantages of the invention will be apparent from the description which follows.